# RUN: echo 'f o o' > %t.0
# RUN: echo 'b a r' >> %t.0
# RUN: echo 'b a z' >> %t.0
# RUN: echo 'f o o' > %t.1
# RUN: echo 'bar' >> %t.1
# RUN: echo 'b a t' >> %t.1
# Due to -w, only third line has a change.
# RUN: diff -w %t.0 %t.1